by Dr.Bouden
How genes involve in the occurrence of cancer?
The DNA in the nucleus of each of our cells contains our gene pool. It is a kind of manual which each page would be a gene. Each gene contains the information necessary for the cell to manufacture specific proteins (all molecules essential to life).
If a gene is faulty (that is to say if an error on a page of instructions), the cell produces the protein incorrectly:
* Or it produces an abnormal protein
* Or it makes a normal protein but too much
* Or it makes a normal protein but at the wrong time.
Normal cells
* They possess genes (called proto-oncogenes) that, upon transfer, to become carcinogenic (they are called oncogenes) and thus initiate a cancer process by converting a normal cell into a cancer cell. Thus it happens that these genes produce proteins evil responsible for regulating the reproductive cells (the cells reproduce by dividing: each gives birth to 2 new cells that are identical in all respects) and / or cell differentiation (each type cell has a specific function).
* They also have genes called tumor suppressors, anti-oncogenes, which prevent the cell from becoming cancerous, even if it has an oncogene. However, these anti-oncogenes may be altered and no longer play their protective role.
Why a gene does mutate ?
There are several reasons for these genetic mutations.
* The cell makes a mistake when her division (called mitosis) to transmit its genetic pool at its 2 'cells - girls', it must make a copy of its DNA (replication). Copy errors occur frequently, but most of time they are repaired immediately. Otherwise, errors are passed on to daughter cells which, therefore, are carrying the genetic mutation.
* The environment can cause genetic mutation viruses, ultraviolet radiation or chemicals can damage DNA and cause the transformation of proto-oncogenes into oncogenes.
How the cell's response to these genetic mutations?
* It has a control system allowing it to detect mutations and thus to repair.
* If it can not fix the error, the cell can self-destruct (apoptosis).
* If the errors (defects) are too numerous, or if the control systems are also damaged, abnormal cells multiply and form tumors.
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One of the causes of cancer is abnormal genes. Cancer causing genes are called oncogenes and genes that prevent cancer are called tumor suppressor genes. Cancers can occur when the normal genes are not functioning normally. Genes, as you know, are the blueprints to the body. They tell a cell what it will be and what it will do. We could not function if the process did not run well. There is a system in place that is designed to keep good genes running and suppress bad genes. This process is called epigenetics.
Epigenetic changes are modifications to the genome that are heritable during cell division but do not involve a change in DNA sequence. Expression of genes is not regulated by the DNA sequence, which is the same in every cell, but by epigenetic marking and packaging. This process regulates chromatin structure through DNA methylation, histone variants, post-translational modifications, nucleosome positioning factors or chromatin loop and domain organization.
How can this cause cancer? Well, if a tumor suppressor gene is abnormally turned off, or an oncogene is turned on, then cancer (carcinogenesis) can occur. One key is a chemical change to the DNA called methylation. First, we need to define the process to make it clearer.
DNA contains four bases: adenine, guanine, cytosine, thymidine, but there is a fifth base methylated cytosine. DNA methyl-transferase (DNMT) produces methyl-cytosine where cytosines precede guanine (CpG). The CpG areas are not symmetric but clustered in CpG islands located at promoter regions. The promoter region is the region at the beginning of a gene and it controls the start of gene transcription. If the promoter is off, then the gene never is expressed.
Abnormal methylation in cancer has been known for 20 years. Hypo-methylated areas turn on normally silent areas such as virally inserted genes or inactive X-linked genes. Hyper-methylated areas silence tumor suppresser genes.
We know that cancers have abnormal levels of methylation and we know foods can help prevent cancers. Is there a link between foods and epigenetics? Yes!
The study of food nutrients and their effect on disease through epigenetics is known as nutrigenomics. This is a growing field, in fact, it is exploding. A Google search for the term nutrigenomics produces 127,000 entries.
Epidemiologic studies suggest there are bad foods and good foods. BAD: red meat, processed meat, grilled meat, dairy, animal fat, partially hydrogenated fats. Good: Fish, fruits, vegetables, tree nuts, omega-3 fatty acids, whole grains.
You can study the epigenetic effects of bad or good foods. I'm going to talk about some of the cancer preventing foods and how their mechanisms include epigenetic effects.
Foods with epigenetic effects include green tea, cruciferous vegetables, and grapes. Usually we hear about antioxidants and foods. Antioxidants are important but there are beneficial substances in foods called polyphenols which can affect genes. Of the polyphenols, different forms exist but flavonoids are the most highly cited for health benefits and are found in a variety of vegetables and fruits. Types of flavonoids include flavanols in tea, isothiocyanate in cruciferous vegetables, anthocyanidins in grapes and berries, flavonone in citrus fruits, flavonols in onions, isoflavones (genistein) in soy.
All tea contains polyphenols, but the highest levels are in green and white tea. Green tea has been well studied and appears to have anti-cancer benefits. In China, green tea drinkers are 50% less likely to develop gastric or esophageal cancer (Carcin 2002; 23 (9): 1497), and 2 cups daily added to topical tea extract reversed oral leukoplakia (J. Nutri Biochem 2001; 12 (7): 404).
Green tea has powerful antioxidant effects but it also helps to balance normal methylation in DNA. In fact, one study in esophageal cancer cells demonstrated that EGCG from green tea is able to turn on tumor suppressor genes that had been chemically silenced by methylation (Cancer Research 2003;63:7563).
Cruciferous vegetables include broccoli, cauliflower, kale, Bok choi and their anti-cancer effects have been demonstrated in epidemiologic studies. These powerful vegetables not only induce enzymes that break down carcinogens but they also inhibit DNA methylation allowing tumor suppressor genes to thrive. Inhibiting abnormal methylation also helps cruciferous vegetables to inhibit the cancer causing action of tobacco smoke by preventing the formation of nitrosamine-DNA adducts.
Grapes, which contain reserveratrol, are excellent for heart health and they have anti-cancer activity. Grapes work by preventing the formation or initiation and promotion of cancers. They don't have methylating actions as discussed above but they work by modulation histones.
Histones are the chief protein component of the DNA chain (chromatin). They act as spools for the DNA to wind around which then shortens the length of the DNA to 30,000 times shorter than an unwrapped strand. This process not only allows the long DNA chain to fit into a cell but also plays a role in gene expression because how the genes are wound affects which are exposed and available for turning on or off. Rolling the spool a different way would expose other genes and change their expression.
Histones are modified after translation by acetylation, methylation, phosphorylation, ubiquitination. The changes occur at lysine residues (except for phosphorylation of serine or threonine). When the histone is acetylated the charge is changed and the histone loosens its grip on the DNA strand and the DNA unwinds, exposing the genes to be transcribed, or repaired.
When histone tails (H3,H4) are acetylated, genes are transcribed, when they are deacetylated, genes are turned off. Histone deacetylases work to maintain deacetylated sites.
Resveratrol, found in grapes, activates Sirtuins; SirT1 (Sir2 proteins). There are at least 7 Sir2-like proteins and they are histone deacetylators. Sirtuins are induced in animals during starvation states. They seem to have a life preservation effect. Interestingly, when an animal is starved, it can live longer. When the calorie intake of rodents was decreased by 40% in rodents, they actually lived 50% longer and appear to have fewer chronic diseases. The same benefit occurs when rodents when they are given resveratrol in their diet.
Resveratrol deacetylates histones causing tighter packing of the chromatin and a lower level of transcription of DNA. This silencing of the DNA is thought to be the mechanism of life prolongation, heart health, and its beneficial actions to prevent cancers. This is why grapes or red wine is beneficial to your health. How much red wine should you drink? No one knows for sure, but any beneficial effects might be negated after two glasses a day because of the alcohol. I wouldn't advise drinking more than this until more is known. The data is very promising, but more research is needed.
Our knowledge of disease expanded in the genomic era due to the human genome project but the study of genes is not enough. Epigenetics is a very important and complicated concept that helps explain how genes are turned on or off. As more studies are completed we will be able to unlock the mechanisms to diseases and produce new therapies that could turn off bad genes and turn on good genes. More importantly, these studies will demonstrate how foods affect your genes and can prevent or reverse diseases or cancers. Nutrigenomics, the study of how food chemicals (nutrients) affect genes, is a growing field and promises to change the way we look at and eat our meals. Some of the most beneficial foods include green tea, cruciferous vegetables and grapes, but don't stop there. The more fruits and vegetables the better when it comes to your health.
Robert Avery MD, is a practicing oncologist in the St. Louis area. He has a keen interest not only in cancer care and therapy but also nutrition and how is helps prevent cancer. He is owner of Citrine Sun, an online company dedicated to helping cancer patients through every stage of their illness through education and natural supplements. An interesting newsletter and information about helpful supplements are available at his website, http://www.citrinesun.com Contact Dr. Avery through his email, AskDrAvery@citrinesun.com
Article Source: http://EzineArticles.com/?expert=Robert_Avery_M.D.
By: illich
A free-radical is a molecule or atom that is missing an electron. Free-radicals attack healthy cells within your body trying to steal an electron from them. Free-radicals are nothing more than thugs.
All cancer is caused by free-radicals and the damage they do to your DNA. Your DNA holds the blue print for every cell that is created. All cancer is caused by mutated DNA. This is how DNA mutation happens; free-radicals attack your DNA trying to steal an electron, this attack continues and changes the blue print within your DNA, now the cells that are being created by your DNA are mutated with this changed blue print. The cells that are produced are cancer cells and the body no longer recognizes them as you; but they are not cancer yet, one more condition is needed to begin the growth of true cancer and that is inflammation. Inflammation appears when there is an injury to our body; even cell injury. Inflammation is there to help heal but it can not heal a mutation so it feeds the cell and within a few years you have some form of cancer.
We can not avoid free-radicals, they are a part of life; they are found in air and water pollution, the processed foods we eat and are caused by trauma and exercise as well as any medication you may take. Medications have a free-radical nature due to laboratory production and doctors call theses free-radicals and the damage they do; side effects.
The only thing that stops free-radicals is antioxidants; they are molecules that have a spare electron. The only place to find antioxidants is in natural sources. Dietary supplements are needed for optimum health and contain some antioxidants, eating natural foods that are un-processed is very important. Processing foods kills the antioxidants and they will not help you.
Most plants have around 1,000 to 1,500 antioxidants each, which does not seem like a lot compared to the amount of free-radicals you are taking into your body every single day; about a billion.
With the discovery of a fruit from South East Asia called the Mangosteen, scientists have been in a buzz about the amount of antioxidants this fruit contains. The Mangosteen fruit has an amazing 25,000 antioxidants. This fruit has been studied in Universities and by scientists for the last 20 years; they have proved that this fruit has the most powerful and the largest number of antioxidants in nature to date. You can read all the studies by going to (pubmed) and typing in Mangosteen. The Mangosteen fruit has also been providing thousands of people with pain relief as well as other medicinal benefits, due to super charged antioxidants called Xanthones. Two hundred Xanthones have been identified in nature, 41 are in the Mangosteen fruit alone and you can compare that to the Aloe Vera plant that contains only one Xanthone. One thing about Xanthones you need to know is that they must be consumed in their natural form.
Cancer and other serious illnesses are on the rise in this country. Cancer is a plague; but we have become so accustomed to the word and the disease that we don’t take it as seriously as we should. Cancer destroys not only the body and our cells; it can destroy our families and devastate our financial situation. (pubmed) is a resource that can be used as a guide to help in your recovery; there are links to several informational pages, done by doctors and scientists.
Alternative health care is also on the rise due to medications that cause so many side effects because of their free-radical nature that you can end up in worse health than when you first went into see the doctor. Medications on top of medications will break down your immune system and the free-radicals end up on a rampage through your body, causing mayhem and destruction, and then you need more medication. All medications carry a risk of side effects. Alternatives such as fruits and veggies do not carry these types of risks. Learn about the amazing power of Xanthones.
Article Source: http://www.kokkada.com
You need a product that will assist with your overall health needs visit: www.mymangosteen.com/amazinglife This amazing juice called Mangosteen is backed up by years of scientific studies done by individual Universities and Scientists click here for more information.
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